This is actually the second issue of the series, as a #0 came out last month. Interestingly, this issue's written by Art Baltazar and Franco, the team on TINY TITANS and BILLY BATSON. I guess they're DC's go-to guys for all-ages stuff these days?

Superboy's alone in Mount Justice, on his first day living there, when he hears the footsteps of another.

From off-panel, someone fires poisoned darts at the two of them, and Snapper goes down.